In the field of lighting technology, and particularly in the lighting technology based on the use of solid-state light radiation sources, such as LED sources, the need is felt to be able to introduce new products with faster reaction times.
At the same time, customers are increasingly asking for customized devices, e.g. customized LED modules, both as regards general lighting and as regards signage applications.
In this scenario, whenever the need arises for a customized device, a dedicated layout is to be designed.
This approach, however, leads to an undesirable proliferation of different products, with consequent management difficulties due e.g. to the proliferation of the ID codes of the single products: this problem, featuring codes identifying products manufactured in very small volumes, or sometimes even only once or twice, may appear e.g. when conventional etching techniques are resorted to in order to produce the circuits.
The etching techniques traditionally adopted to manufacture Printed Circuit Boards (PCBs), e.g. for electronics applications, may involve longer lead times than presently required on the market.
At least theoretically, in order to reduce the so-called time to market, i.e. the time required for the initial marketing of new products, and in order to satisfy at least the first delivery requests, it is possible to resort to printed circuits manufactured in small volumes, e.g. by using rapid prototyping techniques.
This procedure is cumbersome (rapid prototyping has high costs) and it is difficult to use if prototyping is to be followed by high production volumes, e.g. because a different printed circuit may require a new qualification/certification of the product.
In the case e.g. of linear and flexible LED modules, this approach is hardly compatible with the production of continuous LED stripes, e.g. by means of reel-to-reel techniques, because rapid prototyping is adapted to be performed mainly by operating on panels.
Theoretically, it is also possible to produce elongated flexible stripes of a certain length by splicing a plurality of pieces obtained from a panel; this approach, however, may be critical as regards the reliability of the junctions.
The lead time may be shorter in the case of Printed Circuit Boards (PCBs) of the Single-Side (SS) type, i.e. wherein the electrically-conductive lines are implemented only on one side of the substrate, or in the case of Flexible Printed Circuits (FPCs).
A possible solution for decreasing the lead time of new products may therefore involve the exclusive use of this type of printed circuits.
The use of conventional flexible LED stripes may however entail a reduction of the available power, and/or a reduction of the maximum available length. This is due to the fact that, in a Single-Side module, the electrically-conductive lines (tracks), e.g. copper lines, carrying the power supply along the modules are not available on the back (bottom) layer of the substrate.
Another possible solution for satisfying the requirements of reaction time to market and/or of high customizability may consist in using printed circuit boards employing electrically-conductive inks, adapted to be deposited by means of ink-jet printers or stencils, in case of screen printing techniques.
These solutions may hardly be used, however, in mid-high power applications, or for rather long stripes: indeed, electrically-conductive inks have a lower conductivity than metal materials such as copper, and have lower application thicknesses.
For these reasons, the use of electrically-conductive inks is primarily limited to low-power or decorative applications.